Description: (Applicant's Description) The Radiological Sciences core was one of the original cores established at the inception of the University of Colorado Cancer Center in 1988 to provide centralized facilities, training, and expertise for cancer research involving the use of ionizing radiation including irradiation facilities, preparation of radiolabeled cells and antibodies for cancer diagnosis and treatment, radiation dosimetry, and diagnostic imaging consultation services. Cancer center member usage of the 60 Co irradiator has been stable over the last five years and has increased by about 50% for 1999. Radiolabeling services have been used primarily for monoclonal antibody labeling for radioimmunotherapy. This function is projected to increase due to the FDA approval of new antibodies and recruitment of new faculty. Dosimetry consultation services have focused on radiolabeled monoclonal antibodies for radioimmunotherapy as well. The transition to our new campus at Fitzsimons is expected to increase the need for additional facilities for irradiation as Cancer Center members move their research activities to the new site. In addition, the new cyclotron and PET capabilities are expected to increase research opportunities and the involvement of the Radiological Sciences core.